This arm 4, has the 'discs' rather than the mesh cylinder. I drew this up as it best resembled the image I saw in the Star Wars Encyclopaedia [see images]. If you prefer the ‘mesh cylinder’ version, I'll post it up soon [and will link it here]
Arm 4 is a half section, so one half of your print will have to be a mirror version.
The ‘discs’, will require 10 off. printed separately to the arm for a better quality print.
The author marked this model as their own original creation.